/*----------------------------------------------------------
 *				HTBLA-Leonding / Class: 2IHIF
 * ---------------------------------------------------------
 * Exercise Number: 09
 * Title:			Tower of Hanoi Board / Game
 * Author:			Marc Tismonar
 * ----------------------------------------------------------
 * Description:
 * The declaration of an Abstract Data Type representing
 * a game board for Tower of Hanoi.
 * 
 * @see toh_solver.h for details regarding *Tower of Hanoi*.
 * ----------------------------------------------------------
 */

/* == !Include guard and required includes need to be added */
#ifndef ___TOH_BOARD_H
#define ___TOH_BOARD_H
#include "toh_disk.h"
#include <stdio.h>
#include <string.h>
#include <stdbool.h>

/** The enumeration of available rods: LEFT, MIDDLE, RIGHT. */
typedef enum {
    LEFT,
    MIDDLE,
    RIGHT
} RodName;

typedef Disk Rod;

/** Declares type for the 'Tower of Hanoi' board */
typedef struct TohBoardData* TohBoard;

/**
 * Provides the instance of the 'Tower of Hanoi' board.
 * Exactly one instance is supported.
 * 
 * @return TohBoard The board instance.
 */
TohBoard tb_get_board();

/**
 * Removes all disks from any rod of the given board.
 * 
 * @param board The board instance in focus.
 */
void tb_clear_board(TohBoard board);

/**
 * Determines whether or not the given board is valid.
 * A board is NOT valid, if it is 0.
 * 
 * @param board The board to evaluate.
 * @return If the given board is valid, false otherwise.
 */
bool tb_is_valid(TohBoard board);

/**
 * Provides the top-most disk of the given rod and removes it from this rod.
 * 
 * @param board The board instance in focus.
 * @param rodName The rod from which the disk shall be taken and removed.
 * @return The removed disk or 0, if no disk was on the rod.
 */
Disk tb_pop_disk(TohBoard board, RodName rodName);

/**
 * Applies the given disk to the given rod, if this 
 * is allowed according to the rules.
 * 
 * @param board The board instance in focus.
 * @param rodName The rod on which the disk shall be placed.
 * @param disk The disk to place on the rod.
 * @return True if the disk could be legally placed on the rod 
 * (move is allowed and disk is valid), false otherwise.
 */
bool tb_push_disk(TohBoard board, RodName rodName, Disk disk);

/**
 * Provides the disk from the named rod at the given position.
 * 
 * @param board The board instance in focus.
 * @param rodName The rod on which the disk shall be placed.
 * @param idx The index of the desired disk on the named rod. 
 *        Index 0 addresses the bottom-most disk.
 * @return The addressed disk or 0, if not disk is located on the
 *         index position of the named rod.
 */
Disk tb_get_disk(TohBoard board, RodName rodName, unsigned short idx);

#endif